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As its getting warmer managed to start where I left off, Engine was stripped, I did post a thread regarding piston rings etc but prefer to keep all this together, so apart from the rings an a new valve guide needed, I noticed the valve springs were missing the cup and one spacer..... anyway I sourced a new head for the cost of the bits I was missing.....as I plodded on the cams were corroded but the nose was not too bad, eventually splitting the case and the flywheels...... the crank pin is not too bad and could be polished the big end bush is past its sell by date and the rollers seem ok.

Few options,

Make and fit bush/bearing for the conrod and use the existing roller race, replace rollers if possible ? and skim crank pin.

I could buy the bottom crank pin complete with bearing etc but is a bit eye watering at £200 a pop.....

Just wonder if anyone has had any success with their own conversion? I've looked at a few needle bearings I could use but would require some work to fit.

Just looking a bearing site, can buy an inner race which would only need me to machine part of the original in the conrod....

As for the cams..... the corrosion is quite bad and for what I can see of the tappets but they are tight and no play and the feet are ok, are the cams case hardened or the whole thing ? and anyone ever had them re ground ?

Normal bushes etc I can make and will probably make a new one for the timing side of the CC, and renew the rollers, I have some EN 25 steel somewhere.............

So with above is it worth visiting Kempton ? I don't have a bottomless pocket, but would like to get the engine in some reasonable order, but were do you stop.....

I did manage to source a spare head complete with valves and the missing bits I was after for a very good price

Even with all the above and not knowing the condition and what was missing at the start it fired up and run very well, no real obscure noise only the blue smoke.....

Some pics below, don't know who had been been at the crankpin before hand.......

Edited March 7, 2017 by bigduke6

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I presume you must have dealt with Steve Surbey by now? http://www.amcclassicspares.com/ He'll be at Kempton. I'm quite sure the cams are case hardened and probably not worth the cost of getting them ground and hardened as you can buy new ones. Steve sells standard and high lift cams as fitted to the pre war and early G3's. It's worth fitting the HL cams combined with a 276 carb to increase performance as the G3L's were starved a bit due to war economy. They often had a decompression plate fitted under the barrel too. The HL cams involve removing a little bit of material inside the timing case to allow the followers to drop down lower. Very easily done in a few minutes with a Dremmel.

The original crankpins were "two Part" in other words the part that the rollers run on is pressed onto the bit that locates into the flywheels. Someone decided that this could be made in one piece. Makes sense! BUT they were made with a dead square at the step between between the two radius's and this became a fracture point and it was quite common for these pins to break. The cure was to make them with a radius in that corner and subsequently you have to make a corresponding chamfer in your flywheels.

I fitted HL cams to my G3 but went back to standards due to a rattle that I thought was due to the new cams. Turned out it was just some end float rattle on one of my rocker shafts. By now I'd passed the HL cams onto a mate who fitted them in his G3L.....That bike really fly's. Even if it does smoke a lot!!

You obviously have engineering skills and I wouldn't have enough knowledge to advice about mixing and machining parts to make up your big end. For me I would just fit a complete new one. (avoiding those faulty type) My G3 has a needle roller bearing fitted that was made up by a guy who made special big ends for racing and such. (now retired). Ron

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Thanks Ron, Much appreciated (as always) think I need to make the journey down south...... a lot of stuff I can produce but the cams I'll have to bite the bullet and I guess thats most of the timing gear......I found an inner race that I can use on the conrod but i'm sure the pin is a one piece...... and there's me thinking at least the engine would be rebuilt in a week.

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If you DO come down to Kempton, there will likely be a few WD bike nutcases doing the rounds (inc me) and several have G3s. There is usually a meet-up at the burger van between the stand and the huts at 11am. John Tinley is usually there and he may be able to advise......Ron coming?

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Thanks Ferg, After a few calls and a few emails from Ron, located a bottom end, so the ball has started rolling, decided to go for NOS and used (if good) if I can find them, it is tempting from my Engineering point to make and mend, but for what it is the end result will pay dividends.

I hope to get there on Sat, I'll be on the train..... so an early start.

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As normal when I come to do something, another stumbling block....... anyone here used any of the Alpha Crankpin assemblies ?

I cleaned everything up last night to get ready to assemble only to find two of the four oil holes on the pin had not been drilled right through to the centre of the pin ?? so only two will give lubrication. Anyone had the same ?

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I only ever had one dealing with Alpha, who were going to grind the crank and make the big ends for a Harley XA engine for me. After nine months of phoning and false promises and a threat to come up and camp on their doorstep, I finally got my flywheels back untouched. Definitely not a firm I'd want to deal with again. Bike belongs to a friend. Ron

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I only ever had one dealing with Alpha, who were going to grind the crank and make the big ends for a Harley XA engine for me. After nine months of phoning and false promises and a threat to come up and camp on their doorstep, I finally got my flywheels back untouched. Definitely not a firm I'd want to deal with again. Bike belongs to a friend. Ron

Does Janet know you have been putting bike bits on her new kitchen work surface.......

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I used Alpha a couple of years ago and they were OK. Seems some folk have been happy and others, like Ron, clearly not. Pity.......and frustrating for you!

Least of My problems at present Ferg, after cleaning up the outer of the drive side crank case were the bearings sit behind, there was a load of old araldite..... my worst fears were confirmed that the end of the cover had split at some point and hence the araldite etc, I never thought much of it as I was under the impression it was there to make a good seal between this and the inner chain cover, only realised when I was doing a final clean to replace the bearings.

I've got some spares, but have seen a few repairs/mods made to this part were some have made a new separate end cover

(obvious a weak point if someone has been hammering bearings in) just wonder if anyone has done or known of such repairs ?

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Always best to get the cases really hot in the oven first (When Janet is out!) The bearings will almost fall in/out then. This G3 case of mine needed some (TIG) welding as you can see, and the threads remade. So it should be possible to repair your case, especially if it's not completely punched out.

Ron

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Ron, Think I'll get away with one of the HST 2000 repair rods for Aluminium, I was looking on youtube last night when some one built up a threaded hole with the bolt in then removed the bolt etc, My case has suffered the same fate as your G3 one regarding the top threaded hole but only a small bit broken away.

Has anyone here used these rods (see link ) plenty on youtube about them.

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After soaking the bearing etc and blowing through with air I must of dislodged some grease or wax from the protective coating and getting some oil through, the inner race is grooved so whatever position the oil holes are they will get oil.....

Anyway here is the email I got back which was a quick response,

Thank you for your email.

However there is no need for the oil holes of the inner substrate to align with the oil holes of the outer raceway of the crankpin. This is because the outer raceway has a pair of internal annulus grooves to ensure that the oil feed is maintained to all four holes on the raceway irrespective of the angular or polar position.

I trust that this answers your question and that you can continue to assemble your engine with full confidence.

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That seems to be the case Ron, I read something on the internet when someone took over the company he shook it up as it had become quite lax..... I replied to the email and thanked them and received a reply well outside the normal work hours last night.

Back to the crank case..........needs some work, the end had completely broken away, reminds me of my old Honda XL 125, when a shaft sheared and split the Crank Case, the joys of motorcycling... lucky at the time I was on top of a big hill only a few minutes from home, so free wheeled back, (I lived in Cumbria then, hence the hill)

There isn't much left and like fag paper in parts looks like the inner chain case has worn a lot away.

Things are on the up though, won a bid on two sets of crank cases, a few cam shafts, three cylinder heads and several other bits, expected it to go a lot higher than it did, one case set is an early one from contract C9506.

Engine numbers start from 41-G3L- 23800- 25049 for that contract, the case set is 41-G3L-23801 so would belong to frame 19401 and census number 4588176 (I think).

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Good find! You're spoilt for choice now. My own G3L is one from that same contract C9506 #20399 but with a later 1942 engine and several other later parts. The rear frame is one of those that was only fitted to that contract and was revised for the rest built during the war. I think I'm right in saying that mine would originally have had a ribbed front guard and no pannier frames. Ron

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Good find! You're spoilt for choice now. My own G3L is one from that same contract C9506 #20399 but with a later 1942 engine and several other later parts. The rear frame is one of those that was only fitted to that contract and was revised for the rest built during the war. I think I'm right in saying that mine would originally have had a ribbed front guard and no pannier frames. Ron

What was different on the rear frame Ron ?

The job lot win consisted of a few bits I needed, the rest well............ I reckon I'm not far off another full engine may just keep that for a rainy day.... or until an early frame comes along;)

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On these first contract G3L frames, the plates where the rear wheel spindles goes are just sort of welded in place like in this picture. After that the frames were made with proper brazed lugs. They would also have had a drilled for lightness rear sprocket. I know of a couple of guys who are going, or been to great lengths to build one of these 1st bikes to factory spec. Ron

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As the parts are nearly all there for the rebuild (of the engine), I'm in two minds if to use the set of CC's that I bought in a job lot on ebay, as its a vey early set from what I mentioned in a previous post, but if someone knows someone that has an early G3L and desperate for an early set of CC's (I worked it out these where from the second bike to come of the line.... correct me if I'm wrong !)

Below are the CC's in question and also another set which was with them, just curious on the the small little stamp that looks like something similar found on a swiss army knife? these have suffered the same fat as mine regarding the drive side and also a major repair on the case itself.

A cover has been machined up and sits in a machined recess on the case, something similar what I intend to do on mine.

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Duke! Not sure where you're looking up your info? I calculate that engine 26801 is the 1752nd engine from the second contract #C9841. There were no 6 digit engine numbers during the war and I'm wondering if that second engine went through Greek hands?? They often come with strange hieroglyphics.

Very interesting repair to the drive side. Is it just the three primary cover bolts that hold it all together or am I not seeing it correctly?

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I think I'd prefer for that repair plate to be welded in place. But I'm thinking, if crankcase 26801 is in better condition than your original, that could be the one to use? All part of WD motorcycles where although it's nice, it's quite normal to not have matching numbers.

Ron

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Ron, There is not much between the two apart from the original is need of some repairs and I'm half way through making a jacking rig for the tappets, 26801 is probably the better choice just needs the bronze bush's renewed, this has had a repair on the bottom web (you can see it on the pic) just needs tidying up, there are some scars inside the oil pump plunger housing but no worse than the original.

To be honest I've never been a matching numbers person, being a collector of Enfield rifles (Sniper and .22 trainers) there are some who get anal not just about numbers but the parts manufacturer...... mainly Long branch No4 collectors though.

Just making the most of the weather and getting some tin ware done.........

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Progress..... not much but its a start, I managed to source some NOS cams, plust the remainder of parts arrived from Les at Russel Motors (big thanks to him).

With the last spell of good weather managed to strip the main frame, probably not a minute too soon, as the paint just flaked off with a lot of rust and corrosion underneath, not too bad but it showed what lies underneath, after the initial strip, it went through the electrolysis method to get into all the nooks and crannies remove the rust etc, I've used this on many things and can't fault it, cheap and takes about 24 hrs, all it needs is a regular check and to wire brush the oxide off, once dried off and cleaned of all the visible oxide etc, it went into the blast cabinet, as soon as this was done it was cleansed down with thinners and its first coat of red oxide primer. the 4th pic below shows the dark areas of what were rust and corrosion.....

Managed to clean up the crank cases I got on ebay, and have come up ok, and to build up the bottom end with the new bearing, with it in the lathe and set up in various ways it was running within .0001